Mat for sound recording and reproducing machines



Feb. 20, 1923.

' M. M. DESSAU.

I MAT FOR SOUND'RECGRDING AND REPRODUCING MACHINES.

HLED JULY 25,1922- Patented Feb. 26', 192-3.

NITE stares I aaaaaa I ivronnenn MICI-IOLL masses, or Lennon, ENGLAND.

NLAT FOR SOUND RECORDING AND REPRODUCING- MACHINES.

Application filed July 25, 1922.

To all ie/2.0m it may concern:

Be it known that I, MORLAND MICHOLL Dnssao, a citizen of the United States of America, residing at London, England, have invented Mats for Sound Recording and Reproducing Machines, of which the following is a specification.

In the recording of sounds and the subsequent reproduction of sound from the records many forms of yielding supports for the record blanks or for the records proper have been proposed with the object of ol taining faithfulness in the rendering of tones, but none of these, so far as I am aware is in all respects satisfactory.

The object of the present invention is to secure better results and is achieved by the employment upon the turntable of a support or mat of rubber which unlike mossy or spongy rubber having pores filled with inert gas under pressure, already proposed, is more or less cellular or interrupted in character so as to produce air spaces which are in free communication around a multiplicity of separated supporting regions of small dimensions which regions in addition are so disposed that the mat has both faces alike. In this way the rubber is disposed in a manner that is more advantageous, being both capable of yielding to a superior degree when subjected to pressure and rapidly regaining its normal condition when relieved of such pressure.

A mat of this kind is consequently possessed of an enhanced recovery or in other words responds more sympathetically to va riations in pressure so that there is not the same necessity for minute adjustment of pressure at the sound box as heretofore and each side of the mat acting in the same way to resist skidding of the record when the latter is placed thereon.

The conditionsobtaining with a reversible mat according to the invention are not to be confused with those derivable from material built up of alternate layers of perforated and unperforated rubber which produce a multiplicity of isolated cells and con tinuous supporting walls nor from material. having one face provided with studs and the opposite face with cells as has been proposed for stair treads and shock absorbers in general.

Serial No. 577,472.

In the case of a gramophone, a mat of rubber may be employed both surfaces of which are formed with seriesof intersecting ridges, the ridges of one series being more prominent than those of the other, and the more pronounced ridges of an undulating or denticulated character so that protuberances result which may be regarded as reinforced laterally by the less pronounced ridges.

Or in lieu of a mat formed with a definitely patterned surface in relief, a mat can be used both surfaces of which may be smooth or plane. That is to say thin layers or membranes of rubber might be united at y the edges so asto leave a space therebetween which may be occupied by a number of pillars or ties affording small regional supports the space therearound being filled with air at atmospheric pressure or inflated.

The accompanying drawings illustrate how the invention may be carried into effect, Fig. l-being the plan of a mat the surface of which may be similar tothat shown to a larger scale in plan in Fig. 2 and in section in Figs 3 and 4 which correspond respectively to the lines 3, 8 and 4:, 4: of Fig.

2. Fig. 5 is a plan view of another form and Fig. 6 is a section on the line 6-6 thereof. Figs. 7 and 8 are views similar to Figs. 5 and 6 illustrating another modification.

As shown in Fig. 2 ridges a such as indicated in Fig. 3 are intersected by ridges b of lesser prominence such as indicated in Fig. 4. the mat being reversible.

As shown in Figs. 5 and 6 a foundation 0 of rubber is provided on both sides with a multiplicity of separated regions in the form of studs (Z whilst in Figs. 7 and 8 two layers or membranes 6 are separated by pillars f.

What I claim is:-

1. A turntable mat of the character described comprising rubber regional supports and a laminar union of rubber connecting said regions, the disposition of the regional supports in relation to the laminar union of rubber being such that they are stiffened to resist bending or lateral displacement while yielding vertically; the mat having one or more record supporting faces of the same uniform structure.

2. A mat according to claim 1 having its surface formed with series of intersecting ridges the ridges of one series being more one or more sides thereof, the individual prominent than those 01 the other, substanrldges of each series extending substantially tially as described. across the Width of the met. 10 3. A unit for the records of soundrecorda Signed at London, England, this 12th day 5 ing or sound; reproducing machines consistof July, 1922.

ing of a body of flexible material of disk-like form having intersecting series of ridges on MOE-LAND MICHOLL DESSAU. 

